The instrument panel in a car usually has a display in units of kilometres or miles per hour. the displayed value tells you which of the following properties of the car? magnitude of acceleration velocity and acceleration magnitude of velocity velocity

Assume you measured the mass of the cart to be (500 ± 1) g and the mass of the additional mass you put on the cart to be (500 ± 1) g as well. since the scale you are using in the lab cannot measure objects heavier than 600g you will have to sum up individual pieces and propagate the error. so what would be the mass and the standard error of the cart and the mass